RFR: 8302987: Add uniform and spatially equidistributed bounded double streams to RandomGenerator [v10]

[Raffaello Giulietti]

On Tue, 18 Jul 2023 02:54:55 GMT, Joe Darcy <darcy at openjdk.org> wrote:

>> Raffaello Giulietti has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Correction in comment.
>
> src/java.base/share/classes/java/util/random/RandomGenerator.java line 398:
> 
>> 396:              * afforded by nextLong().
>> 397:              */
>> 398:             delta = nextUp(left) - left;
> 
> The delta computations are equivalent to some expression phrased in terms of an ulp (Math.ulp) of a the endpoint or a value adjacent to the endpoint. If the ulp method is not used for the computation, I suggest adding a comment noting the equivalence.

Here `left` is negative or `0.0`. What is needed is the distance to the next adjacent `double` in the direction of positive infinity. This is almost always the same as `Math.ulp(left)`, but not always.
For example, when `left` is `-1.0`, `delta` as computed here is half of `Math.ulp(left)`.

Analogously for the case covered by the `else` arm.

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PR Review Comment: https://git.openjdk.org/jdk/pull/12719#discussion_r1266404939